Complete LOF leads to early-onset, life-threatening infections caused by intracellular pathogens (nontuberculous mycobacteria, BCG) and viruses (typically herpesviruses), reflecting the lack of a STAT1-mediated response to IFN-γ, IFN-α/β, IFN-λ, and IL-27 (139–144). Here, STAT1 is linked to infection.